Associating first and second watermarks with audio or video content

ABSTRACT

The present invention relates generally to processing audio or video content. One claim recites an apparatus comprising: electronic memory for storing media representing audio or video content; and an electronic logic processor. The electronic processor is programmed for: embedding a protect watermark in the media, the protect watermark providing an indication that the media is protected; embedding a rights watermark in the media, the rights watermark providing an indication of user rights associated with rendering the audio or video content, in which the protect watermark is more difficult to remove from the media relative to the rights watermark; and reproducing the audio or video content after said embedding a protect watermark in the media and embedding a rights watermark in the media. Other claims and combinations are provided as well.

This application is a continuation of U.S. patent application Ser. No.12/750,487, filed Mar. 30, 2010 (U.S. Pat. No. 8,095,989) which is acontinuation of U.S. patent application Ser. No. 11/551,607, filed Oct.20, 2006 (U.S. Pat. No. 7,690,041), which is a continuation of U.S.patent application Ser. No. 09/801,515, filed Mar. 7, 2001 (U.S. Pat.No. 7,127,744), which claims the benefit of U.S. Provisional PatentApplication No. 60/188,462, filed Mar. 10, 2000. The above patentdocuments are hereby incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to the field of embedded data, known aswatermarks, and copy control for media.

BACKGROUND

Digital content, including audio, video, images, multimedia, etc., iseasy to copy and expensive to create. Thus, it is a great target forillegal distribution, defined as piracy. Currently, this piracy isoccurring with audio, using MPEG-1 Layer 3 (MP3) bit-rate compressionformat and the Internet. The MP3 format is used by new artist who wanttheir music freely distributed, as well as by people transforming CDaudio into MP3 and possibly illegally distributing it on the Internet.Professional artists and record labels want to stop the second actionwhile allowing the first, and even distribute new content in MP3.

The problem with robust embedded data based methods of protectingcontent in this insecure format is that they are computationallyintense. The prior-art describes numerous examples of such methods usingembedded data (a.k.a. watermarks or steganography) that requirefrequency transformations. Assuming a different watermark is requiredfor each user, player, storage unit and/or content, distributors willneed expensive equipment to protect the data and users will requireexpensive devices to render the content.

The problem with efficient embedded data methods used to protect thecontent in this insecure format is that they are easy to remove, eventhough they can be made robust to duplication, such as utility patentapplication Ser. No. 09/404,291 (U.S. Pat. No. 7,055,034) entitled“Method and apparatus for robust embedded data” submitted on Sep. 23,1999 by Levy, included herein by reference. Removal of embedded data isnot a problem if you require the content to contain the embedded data inorder to be rendered, but this concept only works in a secure format. Inother words, in an insecure format, if the embedded data that informsthe rendering device that the content can or cannot be played isremoved, the content can always be played. However, with a secureformat, removal of the embedded data that informs the rendering devicethat the content can or cannot be played leaves the content uselesssince the device cannot render, such as decrypt, the content withoutthis embedded authorization. For example, in MP3, an insecure formatwhere there is a desire to freely distribute content without protection,the removal of the watermark creates useful pirated content.

Cryptology can also be used to secure the content. However, not only isthis technique computationally intense since it requires many operationsusing a large number of bits, but also one can argue that the format hasbeen changed since existing players cannot play the protected content.

SUMMARY

This object of this novel process is to efficiently protect content inan insecure format using two different layers of embedding data(referred to as watermarks for ease of understanding).

One watermark is robust and declares that the content is protected. Thiswatermark is embedded when the content is created in the desired format,such as MP3, CD or DVD. This means that the computational intensity ofadding the watermark is not an issue because the watermark is only addedto the audio once, and copied with the audio by the distributor. Thiswatermark is labeled the Protect watermark.

The other watermark gives the content its rights, i.e. declares that itis okay to play or record the content. It is efficient, and does notneed to be difficult to removal, since removing it produces noadvantageous results. The efficiency of this watermark is desirablesince it must be embedded each time the audio reproduced, such asdownloaded on the Internet, possibly to link the content to the user,player, recorder and/or storage device. Thus, it greatly reduces thecost of copy management for the distributor. In addition, it lowers thecost of the portable players, since they only have to find thisefficient watermark. This watermark is labeled the Rights Watermark.

To this end, it is desirable to use different types of watermark foreach layer and not two different layers of one watermarking technique.For example, it is not desirable to use one watermarking technique whereone layer is embedded at a low-level, thus being fragile, and anotherlayer is embedded at a higher-level, thus being robust.

Importantly, non-protected content may contain neither watermark and canbe rendered by any device from any storage. Thus, the rendering devicescan be both forward and backwards compatible.

The invented apparatus, which implements the described process, includesan analog or digital logic processor and a storage unit, such a randomaccess memory.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview of the process of using two watermarks to protectcontent in an insecure format with minimal increase in computationalcomplexity, and thus cost.

FIG. 2 displays the pseudocode for the embedding process.

FIG. 3 displays the pseudocode for the retrieving process.

FIG. 4 displays the apparatus.

DETAILED DESCRIPTION

This disclosure begins by explaining the terminology. Content refers tothe data, including but not limited to audio, video, images and smells.Storage refers to device that stores the data. The term watermark refersto any system of embedding data that is minimally perceived when thecontent is played, and is also known as steganography. Data embedded inthe header, and not hidden within the content is still considered awatermark. Robust methods are difficult to bypass. A pirate is anindividual who attempts to illegally copy or distribute the content.

FIG. 1 displays an overview of the invented process. Content 100 existsin an insecure format, which means that non-compliant devices, i.e.devices ignoring copy protection rules, can render the content even ifthe content declares itself as non-renderable. An intrinsic benefit ofan insecure format is that legacy devices, i.e. device created beforethe copy protection system was defined, can render the protectedcontent. In other words, the system is backwards and forwardscompatible. An example of an insecure format is MP3. Some artists wishto freely distribute their content in this format. However, there areother interested parties who want to distribute their content in thesame format without allowing it to be freely copied and redistributed.

The protect watermark 110 declares that the content is protected. Theprotect watermark 110 must be extremely difficult to remove, and,accordingly, may be computationally intense. Many existing watermarkmethods meet this description, and future ones will certainly bedesigned. The rights watermark 120 gives the user rights to render thecontent. This watermark may link the content to the user, player,recorder and/or storage device. This link would determine if the usermay copy and/or play the content. The rights watermark 120 must be acomputationally efficient method that is hard to duplicate. Currently,Levy's application, as referenced above, describes how to designembedded data that is hard to duplicate, i.e. transfer between contentto give rights to content that should not include these rights. However,it is expected that more duplication resistant watermarks will beproduced in the future.

Both watermarks are embedded and retrieved at different times in thereproduction process, as shown in FIGS. 1, 2 and 3. The protectwatermark 110 is embedded when the audio is created, and copied with theaudio when distributed. In addition, the protect watermark 110 is onlyretrieved when the rights watermark 120 does not exist in the content.Thus, the computational intensity of adding the watermark is not thatimportant.

The rights watermark 120 is embedded when the content is reproduced,such as being distributed, placed on permanent storage, or encoded to analternative form by a personal encoding device. The term reproducedrefers to the legal transformation or distribution of the content,whereas copying refers to an individual producing an exact bit-for-bitreplication of the content for legal or illegal utilization. Sincerights watermark 120 is embedded every time the content is reproduced,its efficiency creates a useful reduction in cost for the supportinghardware. Since the rights watermark 120 is embedded after watermark 110it must be okay to layer the watermarks, as known to be possible withexisting technology.

Optimally, the watermarks are search and retrieved in a specific order,as shown in FIGS. 1 and 3. First, the content is searched for rightswatermark 120 (box 300). If rights watermark 120 is retrieved (box 310)the embedded information is evaluated (box 320). If the embeddedinformation is correct, the desired action is enabled (box 330).Alternatively, if the embedded information is not correct, the desiredaction is disabled (box 340). Only if rights watermark 120 is not founddoes the content need to be searched for the computationally intenseprotect watermark 110 (box 350). If protect watermark 110 declares thecontent protected, then the desired action is disabled (box 340),otherwise the desire action is allowed (box 330).

When using a rendering device, such as a MP3 player, which has aportable section, the watermark processing tasks can be split betweenthe loader, potentially a PC program, and the portable section. Thesplit can be designed such that the portable section never needs toretrieve the protect watermark, thus reducing the price of the consumerelectronics portable player by reducing required processing power inthis portable section. For example, when loading the content to theportable section, the loader can check for the rights watermark and theprotect watermark, if necessary. If the desired action for the contentis not allowed, the content is not loaded. If the desired action isallowed, the content is loaded to the portable device.

Then, the portable device may only required to process the rightswatermark, which is efficient to retrieve and embed, for future actions.The portable section would check for the rights watermark 120 if therights watermark 120 contained information the portable device isrequired to understand, such that the portable device can intelligently(i.e. based upon an rules engine) decide how to act upon the content.For example, utility patent application Ser. No. 09/522,312 (U.S. Pat.No. 6,868,497) entitled “Method and apparatus for automatic IDmanagement” submitted on Mar. 9, 2000 by Levy (included herein byreference), requires that the portable section (i.e. portable player)requires the user ID contained in the rights watermark such that theportable section can track usage and intelligently limit it to aspecified number of users, while allowing all content to be previewed.

Finally, this invented process can be used to restrict copying and/orplaying of the content. Since this content is easily created byindividuals and desired to exist on storage in general purposecomputers, it is preferred to use the technology to restrict playing.

FIG. 4 shows the hardware apparatus required to implement the inventedprocesses, such as embedding and detecting the protect watermark 110 andrights watermark 120. The hardware includes a logic processor 400 and astorage unit 410. The logic processor 400 may be defined as theequivalent of a digital signal processor (DSP), general-purpose centralprocessing unit (CPU), or a specialized CPU, including media processors.A likely DSP chip is one of the Texas Instruments TMS320 product line. ACPU could include one of Intel's Pentium line or Motorola/IBM's PowerPCproduct line. The design is simple for someone familiar with the stateof the art given the above pseudocode and description. The storage unit410 includes RAM when using a digital processor.

In addition, a person familiar with the state of the art could implementthe process with analog and digital circuitry, either separate or in anapplication specific integrated circuit (ASIC). The analog and digitalcircuitry could include any combination of the following devices: adigital-to-analog converter (D/A), comparators, sample-and-holdcircuits, delay elements, analog-to-digital converter (A/D), andprogrammable logic controllers (PLC).

The foregoing descriptions of the preferred embodiments of thetechnology have been presented to teach those skilled in the art how tobest utilize the technology. Many modifications and variations arepossible in light of the above teaching. For example, even though thisdisclosure discusses audio and the Internet, it is extendable to othertypes of content and distribution. To this end, the following claimsdefine the scope and spirit of the presently claimed invention.

What is claimed is:
 1. A method comprising: obtaining media representingaudio or video content; using an electronic logic processor: i)embedding a protect watermark in the media, the protect watermarkproviding an indication that the media is protected; and ii) embedding arights watermark in the media, the rights watermark providing anindication of user rights associated with rendering the audio or videocontent, in which the protect watermark is more difficult to remove fromthe media relative to the rights watermark; and reproducing the audio orvideo content after said acts of embedding a protect watermark in themedia and embedding a rights watermark in the media.
 2. The method ofclaim 1 in which the rights watermark includes a link between the mediaand at least one of a user, player, recorder or storage device.
 3. Themethod of claim 2 in which the link determines if the user may copy orplay the audio or video content.
 4. The method of claim 1 in which theprotect watermark is embedded prior to embedding the rights watermark.5. The method of claim 1 in which said embedding the protect watermarkin the media is more computationally intense relative to said embeddingthe rights watermark in the media.
 6. An electronic logic processorprogrammed to perform the method of claim
 1. 7. A method comprising:obtaining media representing audio or video content, in which the mediaincludes a protect watermark embedded therein, the protect watermarkproviding an indication that the media is protected, and in which themedia further includes a rights watermark embedded therein, the rightswatermark providing an indication of user rights associated withrendering the audio or video content, the protect watermark being moredifficult to remove from the media relative to the rights watermark;using an electronic logic processor, analyzing the media to retrieve theprotect watermark only when the rights watermark does not exist in themedia.
 8. An electronic logic processor programmed to analyze the mediaaccording to the method of claim
 7. 9. An apparatus comprising:electronic memory for storing media representing audio or video content;an electronic logic processor programmed for: embedding a protectwatermark in the media, the protect watermark providing an indicationthat the media is protected; embedding a rights watermark in the media,the rights watermark providing an indication of user rights associatedwith rendering the audio or video content, in which the protectwatermark is more difficult to remove from the media relative to therights watermark; and reproducing the audio or video content after saidembedding a protect watermark in the media and embedding a rightswatermark in the media.
 10. The apparatus of claim 9 in which the rightswatermark includes a link between the media and at least one of a user,player, recorder or storage device.
 11. The apparatus of claim 10 inwhich the link determines if the user may copy or play the audio orvideo content.
 12. The apparatus of claim 9 in which the protectwatermark is embedded prior to embedding the rights watermark.
 13. Theapparatus of claim 9 in which said embedding the protect watermark inthe media is more computationally intense relative to said embedding therights watermark in the media.
 14. An apparatus comprising: electronicmemory for storing media representing audio or video content, in whichthe media includes a protect watermark embedded therein, the protectwatermark providing an indication that the media is protected, and inwhich the media further includes a rights watermark embedded therein,the rights watermark providing an indication of user rights associatedwith rendering the audio or video content, the protect watermark beingmore difficult to remove from the media relative to the rightswatermark; an electronic logic processor programmed for analyzing themedia to retrieve the protect watermark only when the rights watermarkdoes not exist in the media.